Heat measuring construction



Jan. V22, 1935. H. G. MCBURNEY HEAT MEASURING CONSTRUCTION Filed oct. 24, 1951 TER UNITED STATES PATENT OFFICE HEAT MEASURING CONSTRUCTION Henry G. McBurney, Roselle, N. J., assigner to Standard Oil Development Company, a corporation of Delaware Application October 24, 1931, Serial No. 570,813

1Claim.

This invention relates to an improved structure for measuring the temperature of a tubular body within a heating chamber.

The invention will be fully. understood from 5 the following description taken in connection with the accompanying drawing in which latter the figure is a side elevational view of a preferred apparatus for carrying out Vthe invention.

Referring particularly to the drawing, reference numeral 1 designates one of a bank of tubes which are connected at their ends by the headers 2 and 4. 'Ihe tubes are disposed within the heating chamber 3 of a furnace with the headers 2 and 4 and adjoining portion of the tubes projecting from tube sheets 5 and 6 of the furnace.

Tube sheets 5 and 6 are supported upon walls 7 and 8 respectively. The bank of tubes may constitute a cracking coil for use in cracking hydrocarbon oil or may be used in other furnaces.

The tubes contain iluid which is passed therethru and to which heat is transferred from the furnace through the walls of the tubes. 'I'he tubes are made of any material commonly used for such service such as steel, nichrome or the like. The headers 2 and 4 are enclosed by header doors 9 and 10 respectively.

In order to measure the temperature of the metal of a given tube within the heating chamber of the furnace an element such as a wire 11 is xed to the tube by peening, clamping, welding or the like at' a given point within the heating chamber of the furnace.

The material of the element is of different thermo-electric properties from the material of the tube and is electrically connected to the tube to form the hot junction constituting a thermo-electric couple. The element is extended through the tube sheet 5 to a position exteriorly of the furnace. A leader 12 of the same thermo-electric properties as the tube is electrically connected to the tube 1 exteriorly of the heating chamber of the furnace. The leader is attached to the tube 1 by means of peening, clamping,

or welding with a metal, the composition of which is the same as that of the leader and tube.

Alternatively the leader can be fixed to the header 2 if the header is of material either similar in composition or possessing thermo-electric properties similar to that of the leader 12 and tube 1. The wire 11 and leader 12 are connected to the terminals 5 of a millivolt meter 14 or the like disposed exteriorly of the furnace and which constitutes the cold junction of the thermocouple.

As a result of the construction described the tube 1 is used as one conductor of the thermo- 1 0 couple. Consequently one thermocouple wire is entirely eliminated from inside of the heating chamber of the furnace with a result that the corrosive effect of the furnace gases on one wire is eliminated thereby prolonging the life of the l5 thermocouple.

Likewise a minimum of labor and material are required for renewing the thermocouple.

A minimum of holes need be drilled into the tubes upon renewal of wires in the furnace.

Various changes may be made within the scope of the appended claim in which it is desired to claim all novelty inherent in the invention as broadly as the prior artpermits.

I claim:

In a coil including a bank of tubes disposed in the heating zone of a furnace and connected by a header disposed in a cooler zone and of the same electric properties as the tubes, means for indicating the wall temperature of the tube bank comprising a wire of different thermo-electric and leader.

HENRY G. MCBURNEY. 

